For many years harvesters, such as agricultural balers, have been used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. Usually, a mower-conditioner cuts and conditions the crop material for windrow drying in the sun. When the cut crop material is properly dried, a harvester, such as a round baler, the most frequently used in the industry, travels along the windrows to pick up the crop material and form it into cylindrically-shaped round bales.
More specifically, the cut crop material is gathered at the front of the baler from along the ground, onto a pickup assembly, and into a crop feeding channel where the material can be further cut before being introduced into a bale-forming chamber. Traditionally, a series of knife blades, known as counter knives, protrudes into the crop feeding channel to assist in the cutting of the crop material. Such knives are mounted for individual release or tripping against a biasing force so as to protect the individual blades from being damaged from obstacles or crop which produces high loads. Additionally, many systems provide a way of selecting all, none, or various numbers of the available knives for operation so as to vary the amount the crop is reduced by the active knives.
DE 43 02 199 discloses one way of selecting the number of active cutting knives. However, this cutting device requires each knife to be individually locked out of operation, which is time consuming and is difficult to achieve in the cramped environment where the cutting device is mounted.
U.S. Pat. No. 6,050,510 discloses a way of selecting the number of active cutting knives wherein a plurality of knives can be locked out of operation according to a pre-selected arrangement by pivoting a blocking rod into a desired location and securing it there for blocking a pre-selected arrangement of knives. While this device does permit multiple knives to be blocked out at the same time, the mechanism for achieving this operation is relatively complex and does not act in concert with the mechanism that allows the knives to form a compact arrangement.
Additional systems, such as U.S. Pat. Nos. 6,394,893, 6,594,983, 6,912,835, and 7,770,371, disclose complex mechanisms for selecting the number of active cutting knives, either by hydraulically controlling each individual knife, or by the rotation of a selection system that activates a certain number of the knives. While such systems do permit the selection of active cutting knives while maintaining a relatively compact arrangement, knives not actively in use are still stored in the machine during operation.
The instant application provides a crop collection system that allows for two trays of cutting knives, each of which can be independently positioned into loaded and unloaded positions. This selectable knife tray arrangement is compact, easy to access, works in concert with the rest of the crop collection system, and allows knives not in active use to be removed from the harvester for maintenance or storage.